The prior art discloses many packaging systems designed for packaging a plurality of containers in six-packs or other larger groupings. However, the containers being packaged are generally ones with rigid side walls and rigid end closure members. These packaging systems are not generally concerned with packaging containers which are constructed of a paperboard laminate material with thin metal end closure structures disposed at either the top and/or bottom ends of the container, such as convolute hot-fill or aseptic extended shelf-life containers described in copending patent application Ser. No. 642,054, filed Aug. 17, 1984, of International Paper Company, the assignee of the present application.
Prior patents that disclose systems for packaging a plurality of rigid container structures which have a particular type of spacer disposed between the cans and shrink wrapping around the cans are U.S. Pat. Nos. 3,062,373 and 3,286,833. Prior patents that disclose carriers formed of a resilient deformable sheet of plastic material having lines of weakness between the individual pockets of the sheet for receiving the end closures of the rigid containers are U.S. Pat. Nos. 3,784,002, 3,300,041 and 3,202,448.
Prior patents disclosing carriers formed of a plastic material disposed over the end closures of a plurality of containers and secured underneath the edge of the chime of the end closures are U.S. Pat. Nos. 4,116,331; 3,871,669; 3,350,131; 3,346,106; 3,331,500; 3,242,631; and 3,200,944.
A prior patent disclosing a plastic carrier for packaging a plurality of containers together that is usable on cans having a beaded or unbeaded rim in U.S. Pat. No. 3,224,576. However, this patent is not concerned with the protection of the end closures or the side walls of the containers being packaged.
A prior patent disclosing a protective cover for a plurality of cans that have a chime is U.S. Pat. No. 3,224,575. The protective cover provides protection to the cans via an upwardly dished member over each container end. However, the protective cover is not configured to prevent the hydraulic effect caused by pressure on side walls of cans which could result in the outward projection of the central panels of the end closures.
Prior patents disclosing packaging systems for large numbers of cans or containers having top and/or bottom trays which engage the chimes of the end closures and further having a means to enclose the containers are U.S. Pat. Nos. 3,650,395; 3,515,272; 3,338,406; and 3,331,502.
The above cited prior art patents do not provide the features of the present invention directed to the protection of the end closures of containers from damage and outward projection due to the hydraulic effect caused by pressure on side walls. Nor are the prior patents concerned with providing a protective packaging system for containers, such as convolute hot-fill or aseptic extended shelf-life packaging containers constructed of a paperboard laminate material and having end closures that are made of a thin metallic material and heat and pressure sealed to the container as is the present invention.